Account takeover via subordinate ID collisions
Published Dec 26, 2024 · Updated Dec 27, 2024
Insecure subordinate-ID defaults in shadow-utils 4.4 through 4.17.0 allow local users to access files as conflicting network accounts. The shipped login.defs assigns each new local account a 65,536-ID range from 100000, and newuidmap can adopt any delegated ID. Exploitation requires a local account, user-namespace mapping support, and an overlapping locally administered UID or GID; successful collisions permit reads and writes as the other account, including on NFS storage.
Summary
What happened
Insecure subordinate-ID defaults in shadow-utils 4.4 through 4.17.0 allow local users to access files as conflicting network accounts. The shipped login.defs assigns each new local account a 65,536-ID range from 100000, and newuidmap can adopt any delegated ID. Exploitation requires a local account, user-namespace mapping support, and an overlapping locally administered UID or GID; successful collisions permit reads and writes as the other account, including on NFS storage.
The record
- CVE
- CVE-2024-56433
- Published
- Dec 26, 2024
- Updated
- Dec 27, 2024
- Vendor
- shadow-maint
- Product
- shadow-utils
- Classifications
- CWE-1188, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 26, 2024CVE publishedPublication date reported by the CVE source.
- Dec 27, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.4 <=4.17.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- subdo.c and subdo.py subordinate-ID proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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